简介：Ayoungcouple,theRobinson's,rentabeautifulnewflatforaboutthehalfthegoingrateofthesameflatsinthebuilding.Poirotispuzzledbythis,whenhehearsthatmanyothershadtriedtorenttheflatandwereturneddown.PoirotbelievesthereissomethinguniqueabouttheRobinson's,andthatwhateveritisthatmakesthemdifferent,thatdifferenceissomehowrelatedtoawomanwhostolesecretAmericansubmarineplansandhasfledtoLondon.AnFBIagenthasjoinedforceswithInspectorJappandhisteamfromScotlandYardtofollowthethiefandrecoverthestolenplans,butthepartnershipbetweentheFBIandScotlandYardisfarfromcordial.…